Modern technology has placed emphasis on electrochemical power sources of light weight, small size, high power and a wide range of working temperatures, coupled with characteristics of long shelf life and fast initial power response.
There are known various reserve cells which are characterized in that the electrolyte is stored in a sealed container which is shattered when the cell is activated, thus contacting the electrolyte with the other components of the cell (anode, cathode and separator) and allowing current to be drawn. Some of the high voltage, high energy density reserve cells are of the type using lithium as anode. Generally, lithium primary cells are known which make use of either an aprotic organic solvent (organic electrolyte cells), or an inorganic solvent (inorganic electrolyte cells). In both cases inorganic salts are dissolved in the solvent to achieve good conductivity.
While the solvent in the case of inorganic electrolyte cells can serve as the cathode depolarizer as well, the organic cells contain additionally a depolarizer which may be soluble or insoluble in the organic solvent.
In both types of cells a porous carbon cathode serves as the catalytic surface on which the reduction of the inorganic solvent itself, or the reduction of the soluble depolarizer or the insoluble depolarizer mixed with the cathode, takes place.
As an example of the prior art there may be quoted U.S. Pat. No. 4,150,198 (1979) of Domeniconi and Murphy for GTE Labs Inc. There is described a reserve cell comprising a lithium anode, separator and carbon cathode, in which the electrolyte comprises a covalent oxyhalide or thiohalide solvent with a Lewis acid as the sole additive solute. A prominent drawback of prior art reserve cells of this type is the long rise time to an acceptable working voltage on current drain and poor power characteristics, particularly at low temperatures. It should be noted that the cathode of the prior art cells is an uncatalyzed, electrically conducting, inert current collector.